Fabrication of PVDF membrane loaded with ultra-thin g-C3N4/FeOCl nanomaterials and study on catalytic and antifouling properties

Membrane separation technology has been widely used in the field of water treatment because of its excellent performance, but the inevitable membrane fouling increases the cost of use. Therefore, in this study, ultra-thin g-C3N4/FeOCl was loaded on polyvinylidene fluoride (PVDF) membrane by vacuum-assisted suction filtration for the first time to fabricate photo-Fenton catalytically modified membranes to improve their antifouling performance. The experimental results showed that ultra-thin g-C3N4/FeOCl adhered well to the membrane surface, increasing the modified membrane's hydrophilicity. In addition, we found that the modified membrane achieved a maximum removal rate of 90% of the fouling. The flux recovery ratio (FRR) increased from 40% to 80% of the original membrane, indicating a significant increase in the membrane's antifouling properties. After 5 cycles, the membrane flux and pollutant removal rate were reduced by only 8%, indicating that the good stability and reusability of the modified membranes. It was experimentally verified that the active species that play a major role in the degradation of pollutants by the modified membranes are •OH and •O2–,the concentration of •OH can reach 5.5 × 10-6 mol/L in 45 min in the presence of hydrogen peroxide and light. In this study, a new modified membrane with good cycling performance is proposed, which provides new insights and ideas for the research of catalytic separation membrane technology.